Correlated disorder and crystal structure of β-VOSO4

Abstract

Pauflerite β-VOSO4 has recently been identified as a one-dimensional S = ½ Heisenberg system, of interest both from a fundamental point of view and a potential material for future spintronics applications. The observation of diffuse scattering in a synthetic β-VOSO4 provides a microscopic interpretation of the underlying correlated disorder, which is linked to the inversion of the short–long V—O distance pairs along VO6 chains, forming a local defect state. Direct Monte Carlo modeling indicates that such defects form thin layers with a positive inter-layer correlation, forming small domains with inverted vanadyl bonding patterns. Two-dimensional defects in anisotropic magnetic systems may perturb, or even destroy, long-range magnetic ordering leading to unusual interactions. In particular, the lack of inversion symmetry in the defect layers opens up the possibility for the Dzyaloshinskii–Moriya interaction (DMI) and, consequently, chiral magnetism localized in the defect planes. The defect β-VOSO4 structure, therefore, opens up new possibilities for the study of low-dimensional magnetic systems.